Process for the manufacture of flexible corrugated walls.



1 W. M. FULTON.

PROCESS FOR THE MANUFACTURE OF FLEXIBLE CORRUGATED WALLS. APPLICATION FILED 001.8, I914.

1 1 92,4 1 2 v Patented July 25, 1916.

ET) attorneys UNITED s'raans PATENT semen.

WESTON M. FULTON, OF KNOXVILLE, TENNESSEE, ASSIGNOR TO THE FULTON COMPANY, OF KNOXVILLE, TENNESSEE, A CORPORATION OF MAINE.

PROCESS FOR THE MANUFACTURE OF FLEXIBLE CORRUGATED WALLS.

Specification of Letters Patent.

Patented July 25, 1916.

To all whom it may concern Be it known that I, WESTON M. FULTON, a citizen of the United States of America, and 'a resident of Knoxville, Tennessee, have invented a new and useful Improvement in Processes for the Manufacture of Flexible Corrugated Walls, which invention is fully set forth in the following specification.

This invention relates to methods of making expansible and contractible corrugated vessels, and more particularly to making the tubular walls of such vessels whereby they will ossess great flexibility combined with dura llity. 7

Heretofore walls for flexible corrugated ,vessels have been made from die-drawn seamless metal tubes and such a method is described in my U. S. Patent No. 975,519. As pointed out in that patent, the operation of die-drawing the seamless metal tube re- 4 sults in hardening the surfaces of the tubular which finally ield to these strains and crack,

thereby terminating the life of the vessel. In my said patent there is also pointed out the desirability of making the flexible corrugated wall of uniform molecular structure and consequently of uniform hardness, toughness and elasticity throughout its cross-section, and there is described therein one method of making such a wall by removing from its surface the outer hardened layers.

I have discovered that a umform molecular condition can be produced metal, such as steel, copper, brass or the l1ke, without removing these outer layers, by'starting with a thicker sheet or wall than is desired in the finished product and working the metal into a thin sheet or wall, the thinness of which varies for difierent metals. When graphic sections of the wall that the less dense central portion has disappeared from between the condensed surface layers and that the condition of the metal as to density, hardness and elasticity is substantially uniform throughout. For example, in the case of soft low brass which I may use for making the walls of my flexible corrugated tubu lar vessels, a thickness of about .008 of an inch is sufficient for reducing the metal to practically uniform molecular condition in the respects noted. My invention which is based on this discovery is capable of expression in a variety of ways or methods of rocedure, one of which, for the purpose of illustration, is herein specifically described; but the method thus described is given solely for the purpose of illustrating the invention and not for defining the limits thereof, reference being had to the appended claim for that purpose.

With a view of assisting the. description, reference is had to the accompanying draw ings, in which g Figure 1 is a transverse sectional View through a die-drawn seamless metal tube used as a blank showing the Stratified condition of the walls in magnified cross-section, Fig. 2 shows the same tube with the outer layers mergedinto each other; and Fig. 3 is a longitudinal sectional view highly magnified showing a collapsible and expansible wall embodying my improvement.

I take a seamless drawn tube such as illustrated in Fig. 1, in magnified cross-section, preferably of soft low brass, and of a diameter suitable to make a corrugated collapsible and extensible wall of the desired dimensions, and subject the tube to repeated drawing operations between a mandrel and a die until the intermediate layer 1 vanishes or until the outer dense layers 2 and 3 merge together into one layer 4 practically homogeneous in cross-section, as can be determined by microscopic examination. For this partlcular material this condition will be secured when.the Wall is reduced to approximately .008 of an inch in thickness. The tube is then corrugated in the customary manner. Such a corrugated tube is shown by way of example in Fig. 3. Should it be desired to produce a wall capable of withstanding considerable pressure, the wall may be laminated in the manner described in my U. Patent No, 979,460. The laminated in the wall, and then corrugating the wall to render the same expansible and con- 'tractible.

' In testimony whereof I have signed this 15 specification in the presence of two sub- SCllblIlg witnesses.

WESTON M. FULTON. Witnesses H. T. PATTON, H. S. MCCOY. 

